Portable power-driven tool



Dec. 8, 1925.

J. J. GEBHARDT ET AL PORTABLE POWER DRIVEN TOOL Filed March 5. 1923 (/caHa/adac/Z Mx 'Patented Dec. V8, 1925.

UNITED STATES JAMES J'. GEBHARDT OSCAR P. WODACK, OF CHICAGO, ILLINOIS, ASSIGNORS TO PATENT OFFICE.

WODACK ELECTRIC TOOL CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OI' ILLINOIS.

PORTABLE POWER-DRIVEN TOOL.

J Application med March 3, 1923. SerialI No. 622,696.

To 'all whom it may concern.'

Be it known that we, J AMES J. GEBHARDT and OSCAR P. WODACK, both citizens of the United States, residing at Chicago, in the county of Cook and State of'Illinois, have invented a certain new and useful Portable Power-Driven Tool, of which the following is a specification.

Our invention relates to improvements in power driven tools such as are used for driving screws after being positioned or in settin nuts. Y

One o the objects of our invention is the provision in portable power driven tools of a construction such that screw driver bits and other attachments may, when desired, be held stationary while the tool isin operation, so as to facilitate the application of the tool to the work.

l0 Another object is the provision of a tool having an improved positive and friction clutch connection between the driving element and the tool attachment.

Another object is the provision of an improved connection between the tool and its power connecting means whereby the tool stops rotating when the screw or nut is driven home, or when the resistance of the screw -or nut exceeds a predetermined U0 amount. 2

A further object is'the provision of animproved tool which is adapted for use with a socket wrench or screw driver attachment to cause their rotation in either direction.

3.5 Other objects and advantages of the' invention will be apparent as the description proceeds. .L In the drawings,

/ Figure 1 is a longitudinal sectional view 4 of the assembled driver.

Fig. 2 is a plan view.

Fig. 3 is sectional view along'the line 3--3 of Flg. 1.

Fig. 4 is a sectional view -along the line 4-4of Fig. 1.- Y

Fig. 5'is sectional view along the line 5.--5 of Fig. 1, and y Fig. 6 is a detail of the ring packing/constituting a frictionclutch. p

In the drawing, the numeral 10 desi ates a cylindrical casln'g having a head 11 axially mounted on one end and a bit 12 and a bitsocket 13 in the' other end. The'headl'l hasathreaded socket 14 in its outer end `fo1f` connection with the spindle of a power driven mechanism.

The casing 10 and head 11 are operatively connected by a friction clutch 15 so thatl rotation of the head normally causes a cor'- responding rota-tion of the casing 10. The bit 12 and bit-socket 13 are mounted for reciprocal and rotatory motion relative to the casing 10 and head 11.

The casing 10 comprising an upper clipsha d ,section 16 and a lower section 17 having threaded engagement which permits their easy separation and assembly. The head 11 is mounted in the section 16 and the bit 12 and the bit-socketl13 in the section 17. The head 11 has a stem 18 extending downwardly substantially through an, aperture 'formed in the bottom 51 of the section 16 and is provided with a'ange 19.

A cap 20 is .apertured to receive the head 11 and is threaded on to the upper end of the casing section 16 until it bears against the upper face of a ber collar 21, which encircles the flange 19. The lower face of the collar 21 rests upon the upper one of a plurality ofv metal rin 22 which are arranged alternately an in vertical alinement with a plurality of libre' rings 23 so as to be supported on thebottom 51 of the cup section 16 to form the friction clutch 15.

V.The fibre rings 23 each have a pair of diametrically'" opposed notches or keyways 9A; formed in their outer ,peripheries The keyways 24 engage corresponding vertical keys 25 which are fastened 011` the inner face of the casing section 16, so that the fibre rings 23 are movable along the keys 25 and cannot be rotated without at the same time rotating the casing 10. The metal rings 22 are of smaller exterior and interior diameters than.. the corresponding diameters of the fibre rings ery of the rings 22 clear'the keys 24 and their inner peripheries fit closely to the stem 18. The openings in therings 23 aremade ofvsuch'siz'e that they clear a key 26 mounted on the stem 18, and sad'key has a sliding fit with corresponding slots or metal .rings 22 so as to cause the rings 22 to rotate with the stem 18 and head 11.

By threading cap 20 downwardly, the col1ar 21 is `ressed against the u per one ofr the meta rings' 22 so as to orce tire 23 so that the outer periphvkeyways 27. in the inner periphery of the.l

- sure radially on,

vso

adjacent faces of the fibre and metal rings together. This contact of the rings forms the friction clutch 15 by means of which rotary movement of the head 11 is transmitted to the casing 10. The clutch 15 is adjusted by turning the cap on or oli as desired. The fibre collar 21 is made suiiiciently to take up the wear in the various parts an prevent binding contact be Ween the flange 19 and the cap 20 or t e adjacent metal ring 22.

The lowerend section of 17 tapers downwardly and inwardly so as to form a seat 23 on which the cylindrical bit-socket 13 is rotatably and reciprocally mounted. The bit-socket 13 has an outer 'collar 30 preferably integrally formed therewith which engages the seat 28 to limit the reciproca movement of the socket downwardly. A metal washer 31 encircles the upper end of the bit-socket 13 above the collar 30 and normally rests upon a seat 32 in the casing, being held thereon by a spiral spring The spring 33 has its upper end bearing against a shoulder 34 formed on the lower end vof the casing section 16 and has its lower end bearing against the washer 31. The seat 32 is positioned above the seat 28 suiliciently to rovide a slight clearance between the was er 31 and the collar 30 which permits a limited reciprocal motion of the bit-socket 13 without moving the washer 31 from its seat.

In the position of the bit-socket 13 shown in Fig. 1 there is no o erative connection between the socket an that the socket is free to" rotate relative to the casing or remain stationary while the casing rotates. A slight longitudinal pressure on the bit 12 is sufficient to move the bit-socket 13 into frictional contact with the washer 31 so that the socket will, 'if desired, rotate with the lcasing 10 and the bit 13 be quickly brou with the screw slot. T e possible rictional contact between the collar and the washer 31 is slight and is limited by the yielding of the spring 33 under pressure. This enablesnthe operator to easily check or stop the resulting rotation of the bit 12 and bit` socket 13fby exerting a slight tinger'presthe socket 13 or upon the shank' of the bit. A i

A pair of -clutch teeth 35 formed on the lower end of section 16 and a corresponding pair of teeth 36 formed von the upper end of the bit-socket 13 provide for positive engagement of the bit-socketwith the casing, 10. This is7^ accomplished by ushing the'bit-socket v`13 and washer 31 against the yielding pressure of the spring 33 up until the teeth 35' vand 36 are in position to mesh.

The teeth are under cut to prevent theirl disengagement while rotating together, and

a're adapted for rotation in either direction deep the casing 10 so y ht into engagementv so that the device is equally as eitective in removing screws or nuts as it is in driving them home.

The bit 12 is operatively connected with the socket 13 by inserting the shank 55 of the bit in a bore 52 formed in the socket. he upper end of the shank 55 has one side -cut away to form a seat 53 adapted to receive a lpin 37 which is mounted in the socket 13 so as to cause the bit 12 and socket 13 to rotate together. The bit 12 is held in operative engagement with the socket by a spring 38 which lits in an annular groove 46 formed in the shank so as to ermit of the easy insertion and removal of the bit from the socket. The spring 38 is ositioned in a kerf 56 formed in the l side of the bit-socket 13 and is fastened by means of a screw 39.

A sleeve 40 is rotatably -and i'eciprocally mounted on the lower end of the bit 12 so as to serve as a combination guide, .centering and. knock-out device. A collar 47 which is fastened tothe bit 12 is adapted to serve as a stop with which an inturned flange 41 formed on the upper end of the sleeve 4() normally engages. The collar 47 is rigidly fastened to the bit 12 by a tapered pin 42 which is mounted as desired in either of the holes 43 in the bit. A spiral spring 45 is mounted in the sleeve 40 with one end bearing against the collar 47 and the other end bearing against a shoulder 48 formed in the sleeve. The pin 42 is inserted through-a hole 44 in the wall of the sleeve 40 after the sleeve is positioned on the bit. The spring 45 yieldingly holds the sleeve 40 in its outermost position as shown in Fig. 1..

The sleeve 40 serves as a center device facilitating the positioning of the bit 12 in enga ement with a screw 49, which has been positioned as shown in Fig. 1.

' In operation, the head 11 being connected with the spindle of a power actuated mechanism rotates continuously driving the casing through the friction clutch 15. The socket 13 and bit 12 are free to rotate with the casing 10 and normally do so by reason of the friction7 in their bearings, but the 'o erator is able to .stop the bit by a Slight radial pressure ou its shank. The sleeve 40 guides the bit into 'axial alinement with the screw 4f) and a slight axial pressure causes the point of the bit to engage the screw slot at a slow velocity. Further axial pressure will cause the spring 33 to yield and the'socket to move upwardly until the tee h 36 engage the teeth 35and the bit be thereby rotated to drive the screw home'.

It will be observed that the Space. separating the socket 13Y from the section 16 (as shown in Fig. 1) is relatively great. This serves to 'prevent the interengagement of the teeth 35 and 3G before the bit 12 locates lll VAmember, a tool-holding mem the screw slot. We have found in practice that an approximate spacing of 3/8 is desirable for this purpose. v

The spring is adapted to yield under slight pressure so thatswhen the sleeve 40 comes into Contact with the face of the work, the bit 12 is permitted to advance relative to the sleeve. When the'spring 45 reaches its maximum compression, the adv-ance of the bit is stopped and its continued rotation drives the screw forwardly so as to automatically become disengaged from the bit. In the event that the screw is to be countersunk, the collar 47 is adjusted to its highest position to permit the descent 'of the bit below the surface of the work; and when the screw is to be driven Hush, the collar is adjusted to its lower position.

It will be observed that the friction clutch 15 operates with equal etliciency in either direction of rotation and .that the teeth 35 and 36 'are also constructed for effective en` gagement regardless of the direction of rotation.y This ada ts the tool for use with both right and le t threaded screws and for removing screws as well as for driving them home. The tool can beused for threading nuts on and off bolts by providing a socket wrench attachment with a shank similar to the shank of the bit 12.

Thus it will be seen that we have provided a tool adapted both to drive screws and set nuts and which automatically stops rotating when the torsional resistance of the screw or nut exceed a predetermined amount. It will be further observed that the tool is adapted for use with both right and left handed screws and bolts to -remove the same as well as to drive them home, and is also adapted for holding screw drivers, bits and other attachments stationary while the tool is in operation so as to facilitate the application of the tool to the work; and still further we have provided an improved guide, centering and knock-out device for mounting on the tool attachments to automatically release the attachment from the screw being driven.

W'e claim as our invention:

1. A' device of the class described havingp` in combination, a driving member connected with a source of power, a tool-holding meniber slidably and rotatably mounted in said member, normally disengaged Acoacting clutch members on said driving member and tool holding member respectively, and resilient means positioned in said driving member to bear against said tool holding member only when it is movedinwardly for engagement of the clutch members.

'2. A deviceof the class described having, in'combination, a rotatable element adapted for connection with a rotar power driven er slidably and rotatably mounted in 'said element, normally Vdisengaged coacting clutch members on said element and holding member respective-ly, a slidable thrust washer seated in the path of and normally out of engagement with the holding member, and a resilient member yieldingly holding said washer on its seat but permitting said holding member and washer to be moved inwardly with said washer bearing on said holding member until said clutch members are in their operatively engaged position and thereby causing said holding member and element to rotate together for an appreciable period before said clutch members engage. e

3. A device of the character described comprising, in combination, a casin-g adapted for attachment to a tool spindle for rotation thereby, said casing having a clutch member ri id therewith, a tool holder rotatable relative to the casin and having a second clutch member rigi therewith, said holder being also mounted for movement axially relative to the casing, and means including a spring acting to hold said clutch members in spaced relation and normally having a bearing in the casing independently of the tool holder whereby to permit relative rotation between the latter and the casing i unrestrained by the action of said spring.

4. A ldevice of the class described com-' prising, in combination, a casing constructed 1n two separate sections rigidly secured together in axial alinement, a member adapted for attachment to a tool spindle and extending into the upper section of the casing, a

friction clutch enclosed within said upper.

section ofthe casing for connecting said member with the casing, a tool holder mounted for relative rotational and axial movements in the flower section of the casing, and means enclosed within the lower section of the casing and providing a positivedriving connection between the casing and the tool holder comprising a pair of clutch members rigid with the tool holder and the casin respectively, andla spring adapted to hol the tool holder in the lower end of the casing whereby to maintain said clutch members normally in spaced relation.

5. A device of the class describedv cofmprising, in combination, a casing constructed v in two separate sections rigidly secured together in axial alinement, a member yadapted for attachment to a-tool spindle and extending intoy the' upper section of the casing, a friction clutch enclosed within said upper section of the casing for connecting said member with the casing, a tool holder mounted for relative rotational and axial movements in the lower section of the casing and means enclosed within'the lower sectionl of the casing and providing a positive driving connection 4between thecasingand the tool holder.y

6. A devicel of 'the character described comprising, in combination, a casing formed prising, in combination, a member adapted in two sections r1g1dly secured together in to be secured to a tool spindle for rotation axial alinement, the upper one of said secthereby, a casing having a friction clutch tions being in the form of a cup having a connection with said member adjustable so 6 cap screw-threaded upon its upper end, and as to permit relative rotary movement behaving an aperture in its botto-m wall, a tween the 4casing and said member when member adapted for attachment to a tool the resistance to the rotation of the casing spindle dependin through said cap and inby Said member exceeds a predetermined to the casing wit its lower end entered in amount, a tool holder mounted in the cas- |0 said aperture, a friction clutch in the upper ing for rotary and axial movements relative section of the casing adapted to connect said thereto, a pair of clutch members rigid' casing therewith, a tool holder mounted in with the casing and the tool holder respecthe lower section ofthe casing for rotational tively, and sprlng means enclosed within the and axial movement therein, spring means easing and acting to hold said clutch mem- IB normally holding the tool holder in the bers in disconnected relation.

lower end of, the casing, and coacting mem- In testimony whereof we have hereunto bers rigid with the tool holder and the aixed our signatures. A

bottom wall of the upper casing section l respectively. JAMES J. GEBHARDT. i0 7. A device of theclass described com- OSCAR P. WODACK. 

